Swim fin

ABSTRACT

A swim fin of fabric type material that is applied to a swimmer&#39;&#39;s appendages for extension between the operative extremity and a location closer the trunk or body of the swimmer. The fin at its midpoint is of a width corresponding to or slightly larger than the associated appendage at such position with fore and aft extensions therefrom being of various shape, size and configurations. The fin is to be attached to the swimmer at its fore and aft ends thereby providing a ballooning effect between the points of attachment during power stroke type swimming movements for the delivery of an increased propulsion effect. Preferably the fin is made permeable to water so a through flow of water will provide a desirable fin shaping effect and fin control.

United States Patent [191 Grivna [111 3,835,493 [4 Sept. 17, 1974 [73] Assignee: J. Wickham Clark, Golden, Colo.

a part interest 22 Filed: Apr. 19,1973

2: Appl. No.: 352,784

FOREIGN PATENTS OR APPLICATIONS 712,295 /1941 Germany 9/307 Primary Examiner-Trygve M. Blix Assistant Examiner-Gregory W. OConnor Attorney, Agent, or Firm-C. B. Messenger [5 7 ABSTRACT A swim fin of fabric type material that is applied to a swimmers appendages for extension between the operative extremity and a location closer the trunk or body of the swimmer. The fin at its midpoint is of a width corresponding to or slightly larger than the associated appendage at such position with fore and aft extensions therefrom being of various shape, size and configurations. The fin is to be attached to the swimmer at its fore and aft ends thereby providing a ballooning effect between the points of attachment during power stroke type swimming movements for the delivery of an increased propulsion effect. Preferably the fin is made permeable to water so a through flow of water will provide a desirable fin shaping effect and fin control.

9 Claims, 9 Drawing Figures 1 SWIM FIN BACKGROUND OF THE INVENTION In order to improve the swimming capabilities of individuals, various types of swim fins and paddle equipment have previously been devised. At present only the swim fins that are attached to the users feet are in widespread use. Other forms that are intended for attachment to the users hands or arms are not generally utilized, since most previous attachments have probably impaired or obstructed natural movements of the arms. Where relatively rigid or even moderately flexible components are used, a substantial interference with return stroke operations is noted, and, accordingly, the overall effectiveness of such prior designs has been limited. The advantages that may be gained in power stroke operations through use of some prior devices is often and regretably offset by return stroke swimming movements.

SUMMARY OF THE INVENTION In order to avoid the difficulties inherent in earlier designs and in an effort to provide a swim fin that will have a power stroke advantage without a concomitant return stroke disadvantage, the presentinventor provides a swim fin construction wherein the main body of the device is made of a fabric type material that is inherently loose and flexible. The swim fins are attached at their longitudinal ends to the swimmers appendages. The natural movement patterns of a swimmers arms or legs through the water during a power stroke then provide a ballooning effect for the fabric structure as the fin resists movement of the users appendage through the water to thereby add an increased propulsion effect. On the return stroke the fabric structure of the fin collapses about the users appendage, and the resistance to movement of the appendage is then not substantially greater than the natural resistance for normal return stroke movements. The swim fin body is preferably made of a water permeable material so that a minor flow of water therethrough will be experienced during power stroke operations with such flow being operative to control the positioning and shape of the swim fin. Where non-pervious materials are used, openings of distinctive shape and positioning ca be provided to accomplish such control function. Various attachment means and devices are incorporated to facilitate the application and use of the swim fins.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a first embodiment of the invention applied to a users arm,

FIG. 2 is a layout diagram for the embodiment of FIG. 1,

FIG. 3 is an elevation showing the forward end of such embodiment,

FIG. 4 is an end elevation showing such end in a position of application,

FIG. 5 is a perspective view showing an alternate 'embodiment of the invention,

FIG. 6 is a perspective view showing a third embodiment of the invention applied to a users arm,

FIG. 7 is a layout diagram for the embodiment of FIG. 6,

FIG. 8 is an elevation showing the forward end of the FIG. 6 and FIG. 7 embodiment as applied, and

FIG. 9 is a perspective view of a fourth embodiment or adaptation of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The general principles of the invention are illustrated in a first embodiment shown in FIG. 1, where the swim fin 11 is shown as applied to a swimmers arm. The body 12 of the fin 11 is made of a pervious type material, such as the cloth fabric illustrated. The fibers 13 of the woven or knit cloth body 12 may be of natural or synthetic material providing various textures or weaves, so long as the entire body 12 is at least in minor measure permeable to water. Most natural fibers will be wetted when the fin is in water, and water will be transmitted from one surface of the cloth to the other if subjected to a flowing stream of water or if the fin is moved with respect to flowing or relatively stationary water. The actual degree of permeability may be varied for separate uses between that noted with a quite loosely woven sieve type of cloth to an alternate type of tighter fabric where a through flow of water would not be established or noticeable under a pressure head of several inches of water. For desirable materials of lesser penneability some flow or drainage should be experienced if the surface of the material away from actual contact with the water is wiped, as by a finger or blade. Where various types of manmade or synthetic fibers are used, the fiber itself may not be wetted by exposure to the water and yet the desirable and beneficial permeability can still be established with proper regulation of the yarn size, the weave pattern, and the denier of the cloth.

For this first embodiment of the invention as shown in FIGS. 1 through 4, a fabric 13 of satisfactory penneability provides the body structure 12 which can have a layout pattern substantially as shown in FIG. 2. The body 12 is attached, as by stitching 14 and 16 applied at its longitudinal ends, to an upper band support 17 and an outer band support 18. The band supports may be of a tape like material which has a substantial strength characteristic in contrast to the actual strength of the fabric 13 itself. Velcro type fastener elements,v

inclusive of looped fabric pieces 19 and hook catches 21, are applied to the ends of the bands 17 and 18. The upper band 17 is thus adapted to be adjustably secured about the users arm 22 at a position adjacent the elbow 23. The band 17 is wrapped about the arm in such position, and the Velcro fastener elements 19 and 21 are attached to hold the band and, accordingly, the swim fin body structure 12 in applied position on the arm. The outer band 18 is adapted to be engaged about the palm of the users hand 24 with the band disposed just forwardly of the thumb 26.

As illustrated in FIGS. 3 and 4, the outer end 27 for the swim fin body 12 is not sewn directly to the band 18 in positions away from its "points of attachment by the stitches 16. With such arrangement the outer end 27 is free to raise above the band 18 thereby providing an entrance opening 28 through which water will flow for introduction beneath the body 12 of the swim fin and above the upper surface of the users arm. When properly applied and used, the swim fin 11 will balloon above the users arm as the swimmer executes a power stroke. At positions of maximum resistance the swim fin should assume a curved domed configuration about the swimmers arm, as shown in FIG. 1, with the actual fabric body 12 being spaced from 1% inches to approximately 3 inches distance above the swimmers arm.

The actual conformation of the desirable ballooned or billowing shape may be facilitated through provision of intermediate stays 29 and 31 which are sewed or otherwise attached to the body 12 in the approximate positions illustrated. The stay pieces, which may be of metal or plastic, should have at least a slightly arched configuration that will easily move to the full domed configuration in resistance to arm movements and the resultant flow of water impinged against the body 12 itself.

In general, it is believed that it is the pervious characteristic of the fabric 13 which establishes the main shaping control features of the swim fin, but in some instances the use of the arched stays has tended to improve the results obtained especially when the fins are being used for a first time. A main purpose for the control features, whether embodied in the use of stays or only in use of a permeable material itself, is to attain a desirable billowed or full sail configuration without detrimental collapse or fluttering as the swimmer moves through a full power stroke.

For this and all other embodiments of the invention, the construction should have a full collapsed characteristic when a return stroke is to be accomplished. The fabric of the body 12 and the stays, etc., should move toward the swimmers arm and be flattened or collapsed thereabout as the arm moves forwardly in anticipation of a next power stroke. With the swim fin l 1 collapsed about the swimmers arm, there is no substantial increase in the resistance experienced in the accomplishment of such movement, and no penalty is incurred that inhibits or lessens swimming capabilities.

For the second embodiment shown in FIG. 5, the only substantial modification includes the provision of a finger halter 32 that is attached to the forward end 27 of the swim fin 11A. All other components may be of construction similar to that previously described. Accordingly, an identical numbering system is applied thereto. The halter 32 has a ring component 33 that is to be looped about the second or third finger of the swimmers hand. This halter may then be used to somewhat control opening and closing of the flow passage 28 as the users wrist or fist is moved. For this embodiment of the invention, the stays have been eliminated, and a heavier tape 34 is seamed to the lateral edges 36 and 37 of the body construction 12A. Heavier or reinforced construction along such lateral edges can itself provide an improved control feature for the swim fins.

A third embodiment of the invention is shown in FIGS. 6, 7 and 8. Here the swim fin 118 has a body 123 that isagain of a pervious type material, since a fabric 13 is used in the construction. The upper band 17 again provides a Velcro type fastener system, but the outer band 38 is of difierent construction. Band 38 is formed of an elastic type of tape with the body structure 128 being stitched to the elastic band at the stitch points 39 and 41. The elastic of the band 38 is initially of a looped construction with the original loop configuration being divided into a thumb loop 42 and a finger loop 43 through application of stitches 44 or other fastening means, as shown. When this type of swim fin is used, the thumb loop 42 will be engaged on the swimmers thumb 46 at a position adjacent the first joint thereof. The finger loop 43 is engaged across the fingers in position adjacent the second joint. As in the previous embodiment, the forward end 47 for the body 128 is of greater length than the flat projected length for the looped band 38, and, accordingly, a flow entrance 48 is still provided. The body 128 is of truncated tapered shape from its base edge 47 to its upper edge 49. Prearched stays 29B and 31B are again provided. Increased swim fin control is available in connection with use of this embodiment of the invention, since the looped band is of elastic material, and it may, accordingly, be stretched or contracted during periods of use. If the fingers and thumb are spread more widely apart, the opening at the flow entrance 48 will be modified. At the same time the projected area of the body 128 is increased, and a different flow pattern will be established. Such changes in projected areas and in flow characteristics can substantially change the propulsion effects gained during power stroke swimming operations. Different fin configurations are often desirable or beneficial where different swimming strokes or swimming operations are undertaken. The adaptability of the features of the embodiment shown in FIGS. 6, 7 and 8 are, accordingly, of special advantage.

A fourth embodiment of the invention is presented in FIG. 9. This swim fin 11C has a body 12C that is formed of a non-permeable type of material. In order to provide the desired control functions, one or more holes 51 or diamond shaped slots 52 or slits 53 are provided in the body material 12C. Water will pass through these openings when the fin is subjected to dif ferential pressure influences. For this swim fin a nonelastic type of outer band 58, which has a thumb loop 62, is provided. A snap or Velcro fastener 64 may be provided in the finger loop portion 63 to facilitate application and usage.

In the use of all embodiments of the invention it presently seems desirable to maintain a smoothly billowed but full contour for the swim fin as swimming strokes are being completed. Some operations have indicated, however, that the fully billowed shaping should not be established with the body of the fin still being positioned in close proximity to the upper surface of the users arm or appendage. If the fabric body is positioned closely to the arm or if it moves into such position, a collapse of the billowed shaping often results. Apparently the flow characteristics for the water as it moves about the swimmers arm tends to create a zone of decreased pressure that is seemingly not unlike the pressure influences operative on the upper surface of an aircraft airfoil. This flow characteristic is recognized, and means for the beneficial usage of such char acteristic are especially incorporated in embodiments of the invention. The finger halter of FIG. 5 and the elastic looped band of FIGS. 6 through 8 provide the swimmer with added capability to control the proximity of the fin body to the arm. With these and similar configurations, the billowed shaping of the fin could be established or collapsed at will to provide distinctive and separately beneficial swimming characteristics.

While features of the present invention have been shown and described in connection with swim fins that are to be applied to a swimmers arms, other fins incorporating the same beneficial features can be provided for attachment to the swimmers legs. Accordingly, the total development is directed to the provision of swim fins that may be applied to a swimmers appendages.

I claim:

l. A swim fin for application to a swimmers lower arm to provide an increased propulsion-effect comprising a lower support for engagement adjacent the swimmers hand, an upper band support for engagement on the arm at a position adjacent the elbow of the swimmer, a body element of flexible water pervious sheet material that is of cross-sectional width corresponding to the projected width of the swimmers arm at a midpoint of said body element attached to said lower support adjacent each edge of said body element and extending loosely between said edges and said upper and lower supports for water induced movement to alternate positions either collapsed to conform with the swimmers arm during return stroke movements or billowing therefrom when the arm is moved through water I in an opposite direction during power stroke movements to provide the increased propulsion effect.

2. The swim fin of claim 1 wherein the body element is of width not greater than one and one-half times the projected width of the swimmers arm at a midpoint of 5. The swim fin as set forth in claim 3 wherein defined openings are provided through said sheet material.

6. The swim fin as set forth in claim 1 wherein an adjustable fastener is provided for at least one of said supports for selectively attaching said swim fin to a swimmers appendage.

7. The swim fin as set forth in claim I wherein said body element is attached to said lower support at positions that are laterally spaced with respect to the swimmers arm and hand providing an entrance opening between said spaced attaching positions for the introduction of water above the swimmers hand and beneath said body element during power stroke movements.

8. The swim fin of claim 7 and further comprising a flexible band for said lower support and wherein said flexible band is disposed about the swimmers hand and wherein separate loops are provided by said flexible band for separate engagement about the swimmers finger and thumb.

9. The swim fin as set forth in claim 7 and further comprising a finger loop attached to said body element centrally of said entrance opening and adapted for engagement about the swimmers finger for regulating the water admitting flow capacity of said opening. 

1. A swim fin for application to a swimmer''s lower arm to provide an increased propulsion effect comprising a lower support for engagement adjacent the swimmer''s hand, an upper band support for engagement on the arm at a position adjacent the elbow of the swimmer, a body element of flexible water pervious sheet material that is of cross-sectional width corresponding to the projected width of the swimmer''s arm at a midpoint of said body element attached to said lower support adjacent each edge of said body element and extending loosely between said edges and said upper and lower supports for water induced movement to alternate positions either collapsed to conform with the swimmer''s arm during return stroke movements or billowing therefrom when the arm is moved through water in an opposite direction during power stroke movements to provide the increased propulsion effect.
 2. The swim fin of claim 1 wherein the body element is of width not greater than one and one-half times the prOjected width of the swimmer''s arm at a midpoint of said body element.
 3. The swim fin of claim 1 wherein the flexible pervious sheet material of said body provides a minor flow of water through said body during at least the said power stroke movements.
 4. The swim fin as set forth in claim 3 wherein said body element is formed of a fibre derived woven fabric.
 5. The swim fin as set forth in claim 3 wherein defined openings are provided through said sheet material.
 6. The swim fin as set forth in claim 1 wherein an adjustable fastener is provided for at least one of said supports for selectively attaching said swim fin to a swimmer''s appendage.
 7. The swim fin as set forth in claim 1 wherein said body element is attached to said lower support at positions that are laterally spaced with respect to the swimmer''s arm and hand providing an entrance opening between said spaced attaching positions for the introduction of water above the swimmer''s hand and beneath said body element during power stroke movements.
 8. The swim fin of claim 7 and further comprising a flexible band for said lower support and wherein said flexible band is disposed about the swimmer''s hand and wherein separate loops are provided by said flexible band for separate engagement about the swimmer''s finger and thumb.
 9. The swim fin as set forth in claim 7 and further comprising a finger loop attached to said body element centrally of said entrance opening and adapted for engagement about the swimmer''s finger for regulating the water admitting flow capacity of said opening. 